It has become conventional practice for carrying ladders and the like on racks mounted on motor vehicles to provide the rack with mechanical clamping members to secure the ladder to the rack. Such clamping members eliminate the need for ropes and elastic ties, which may loosen or break during use, with the resulting possibility the ladder may fall from the rack and cause damage or be damaged itself.
In practice, however, known clamping arrangements may suffer from numerous disadvantages. They can be heavily sprung and cumbersome, and therefore difficult to latch or unlatch, particularly where the user has limited strength. In addition, they may protrude from the rack, making sliding and placement of the ladder difficult and clumsy. The clamping members can also be complicated, employing numerous linkages and rotating handles, which can add to the expense of manufacture and increase the likelihood of failure.
Another problem that has arisen in the use of clamping members is the inadvertent closing of the clamping members when the ladder is being placed on the rack. This problem occurs where the clamping members are biased in the closed position and manually held open to receive a rung of the ladder. If the user is unable to hold the clamping member open continuously it may close prematurely, possibly damaging the clamping member or the ladder, and/or causing significant injury to the user, such as where the user's hands are disposed at the rung to be engaged by the retaining device when the inadvertent movement occurs.
Accordingly, it is an object of the present invention to provide a clamping arrangement for securing a ladder to a vehicle rack which is reliable and simple to operate. It is a related object of the invention to provide a clamping arrangement which does not protrude beyond the top surface of the rack when the ladder is moved into position.
It is a further object of the invention to provide a clamping arrangement which is biased to remain open when the ladder is placed on the rack, and is also biased to hold the ladder securely and reliably in place once the clamping arrangement is closed or engaged.
It is yet another object of the invention to provide a clamping arrangement which is inexpensive to maintain and to manufacture, and which may be adapted to a variety of ladder racks normally available in the marketplace.
It is also an object of the invention to provide a clamping arrangement which is quick and simple to secure in position and which is inherently durable and long lived.
Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings.